Tayassu pecari (Link, 1795) (Mammalia,Cetartiodactyla): comments on its South American fossil record,taxonomy and paleobiogeography

Tayassu pecari is widely distributed across the Neotropical region, from northern Argentina to south-eastern Mexico. However, its fossil record is scarce; it is recorded since the middle Pleistocene to Holocene in Argentina, Brazil and Uruguay. This paper aims to: (1) update the systematic synonymy of this species; (2) review and update its geographic chronologic distribution and provide a new Lujanian record of Tayassu pecari in Buenos Aires Province and (3) discuss the paleoenvironmental and paleobiogeographical implications of this record. Considering the quantitative analysis performed, the fossil here recorded clearly integrates the group of Tayassu pecari. This specimen corresponds to the first record of Tayassu pecari in the central-northern region of the Buenos Aires Province. During Late Pleistocene, Tayassu pecari was distributed southern to its recent range, probably evidencing different paleoenvironment conditions. This species is the better adapted peccary to tropical and subtropical rainforests, but may also be present in arid environments. Consequently, Tayassu by itself is insufficient to infer the prevailing environmental conditions. However, according to the fauna associated with the specimen described here, it is possible to infer an open or semi-open and arid or semi-arid environment for the central-northern Buenos Aires region by Late Pleistocene times.     

The Chacoan peccary,Catagonus wagneri (Mammalia,Tayassuidae), in the late Pleistocene (northern Uruguay,South America): paleoecological and paleobiogeographic considerations

Catagonus wagneri has the most restricted geographical distribution among extant Tayassuidae and inhabited semi-arid thorny forests of dry Chaco in Paraguay, Bolivia and Argentina. Until now, C. wagneri has only been recorded in archaeological, pre-Hispanic deposits from the Santiago del Estero Province, Argentina. A new partially complete skull from the Sopas Formation (Late Pleistocene; Uruguay) is identified as C. wagneri. This is the only fossil record of the species which extends its biochron until the late Pleistocene, and the first one substantially far from its current range; the first fossil record of the species in Uruguay; the most complete fossil material of the species; and it provides relevant ecological and climatic information. According to the ecological and climatic available information of C. wagneri, the presence of this mammal in the late Pleistocene of northern Uruguay indicates a warm climate and arid to semi-arid environments. Even though not associated with the fossil remains of C. wagneri, some mammals included in the sedimentary levels of the Sopas Formation also suggest arid to semi-arid environments. Climatic changes, in particular in the late Pleistocene and Holocene, could be invoked to explain modifications of its geographic range.http://zoobank.org/ECF04BCF-8246-4F11-AAB8-5FAA9F437BDA     

Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae), a newly recorded parasitoid of the tomato moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), in Argentina

We report the first record of Neochrysocharis formosa (Westwood) parasitizing larvae of the tomato moth, Tuta absoluta (Meyrick), in tomato crops in Northern Buenos Aires Province, Argentina. Tomato moth larvae were sampled during four consecutive growing cycles, between 2003 and 2005, in 10 sites. Neochrysocharis formosa was present only in organic outdoor and protected crops, and predominantly during the late season. Parasitism rates varied from 1.5% to 5%. The finding of this species is a new record for Argentina and South America, and T. absoluta is a new host record.     

A giant vampire (Mammalia, Chiroptera) in the Late Holocene from the Argentinean pampas: paleoenvironmental significance

The first fossil desmodontine record and the only well documented chiropteran fossil record from Argentina is described. A complete left upper canine was collected at Centinela del Mar (38°21′S58°W, General Alvarado County, Buenos Aires Province) from fossil-bearing sediments referred to the Late Holocene. The tooth size is 25% larger than that of the modern vampire bat, Desmodus rotundus. We assign this tooth to Desmodus cf. D. draculae, an extinct species recorded in the Pleistocene–Holocene of South America (Brazil and Venezuela). The southernmost distribution of present-day Desmodus extends to northeast Buenos Aires province (35°S). The presence of Desmodus some 600 km south of this present-day limit (July minimal isotherm of 10°C) indicates that around 300 years BP the southeastern Buenos Aires province was at least 2°C higher than modern July isotherm. The Desmodus tooth is associated with sigmodontine rodents characteristic of subtropical and temperate-warm areas (e. g., Pseudoryzomys simplex, Bibimys cf. B. torresi), and provides additional evidence to support this hypothesis. A correlation with a global warming phase is discussed.     

Parachoerus carlesi (Mammalia,Tayassuidae) in the Late Pleistocene (northern Argentina,South America): paleoecological and palaeobiogeographic considerations

Abstract

The Tayassuidae is one of the first families of North American immigrant mammals that arrived into South America during the ‘Great American Biotic Interchange’. They have been found associated with Late Cenozoic deposits mainly in Argentina and Brazil, but also in Uruguay, Bolivia, Colombia, Peru and Venezuela. Theirs records within Argentina come from the Pampean Region, Mesopotamia and north-central region. Here, we report the first record of P. carlesi with precise stratigraphic (26.630 ± 370 14C years BP, Late Pleistocene) data in Argentina, precisely from the Chacoan region. This specimen represents the most complete fossil material of this extinct species, increasing its morphological and morphometrical knowledge, and it provides relevant ecological and climatic information. From a palaeoenvironmental point of view, the fauna registered in this paleontological site, includes taxa mainly adapted to open or semi-open and arid or semi-arid environments. The bearing sediments and the peculiarities of the faunal assemblages, as well as the chronological data, allow confirming that arid and semiarid conditions, with scarce or absent vegetation cover were developed in this area of Argentina during the last part of MIS 3 and beginning of MIS 2. These environmental conditions favored the settlement of megamammals adapted to open environments.     

Fossil moonseeds from the Paleogene of West Gondwana (Patagonia,Argentina)

Premise of the Study

The fossil record is critical for testing biogeographic hypotheses. Menispermaceae (moonseeds) are a widespread family with a rich fossil record and alternative hypotheses related to their origin and diversification. The family is well‐represented in Cenozoic deposits of the northern hemisphere, but the record in the southern hemisphere is sparse. Filling in the southern record of moonseeds will improve our ability to evaluate alternative biogeographic hypotheses.

Methods

Fossils were collected from the Salamanca (early Paleocene, Danian) and the Huitrera (early Eocene, Ypresian) formations in Chubut Province, Argentina. We photographed them using light microscopy, epifluorescence, and scanning electron microscopy and compared the fossils with similar extant and fossil Menispermaceae using herbarium specimens and published literature.

Key Results

We describe fossil leaves and endocarps attributed to Menispermaceae from Argentinean Patagonia. The leaves are identified to the family, and the endocarps are further identified to the tribe Cissampelideae. The Salamancan endocarp is assigned to the extant genus Stephania. These fossils significantly expand the known range of Menispermaceae in South America, and they include the oldest (ca. 64 Ma) unequivocal evidence of the family worldwide.

Conclusions

Our findings highlight the importance of West Gondwana in the evolution of Menispermaceae during the Paleogene. Currently, the fossil record does not discern between a Laurasian or Gondwanan origin; however, it does demonstrate that Menispermaceae grew well outside the tropics by the early Paleocene. The endocarps’ affinity with Cissampelideae suggests that diversification of the family was well underway by the earliest Paleocene.     

First fossil record of the catfish genus Sorubim (Siluriformes,Pimelodidae), from the Late Miocene of Paraná, Northeastern Argentina

The aim of the present contribution is to describe a partial fossil skull belonging to the catfish genus Sorubim. The specimen originates from the Late Miocene Ituzaingó Formation, at Paraná locality, Entre Ríos Province, Argentina. The material described here (MACN Pv-14224) was determined just to genus because the living species of Sorubim are morphologically similar. Presence of Sorubim is in concordance with the hypothesis indicating that most extant pimelodid genera were already present by the Late Miocene. Present finding constitutes the first fossil record for the genus.     

Recent genus Notonecta (Insecta: Heteroptera: Notonectidae) in the Lower Cretaceous of San Luis,Argentina: Palaeoecological implications

We describe a new species of the genus Notonecta, i.e. Notonecta mazzoniae n. sp. from the Lower Cretaceous of Argentina. It is the first fossil representative of the family described from South America, demonstrating the great antiquity of the genus, bearing identical ventral chaetal system correlated with respiratory for such a long period. The new species is recorded only by immature stages from the second to the fifth instars. Specimens are considered to be exuviae and not body fossils. Absence of body fossils may be due to taphonomic bias instead of palaeoecological constrains. In addition we found some specimens of Anisopinae, also considered as nymph exuviae, which represent the oldest record of the taxon.     

A long-living species of the hydrophiloid beetles: Helophorus sibiricus from the early Miocene deposits of Kartashevo (Siberia, Russia)

The recent hydrophiloid species Helophorus (Gephelophorus) sibiricus (Motschulsky, 1860) is recorded from the early Miocene deposits of Kartashevo assigned to the Ombinsk Formation. A detailed comparison with recent specimens allowed a confident identification of the fossil specimen, which is therefore the oldest record of a recent species for the Hydrophiloidea. The paleodistribution as well as recent distribution of the species is summarized, and the relevance of the fossil is discussed. In addition, the complex geological settings of the Kartashevo area are briefly summarized.     

Taphonomy of modern communal burrow systems of the Plains vizcacha (Lagostomus maximus,Chinchillidae) in the Pampas region of Argentina: implications for the fossil record

The Plains vizcacha (Lagostomus maximus) is one of the largest rodents in South America. They live in communal burrow systems (vizcacheras) shaped by complex subterranean galleries which produce a strong impact on the local landscape. This paper presents the results of an actualistic study conducted with abandoned vizcacheras from the Pampas region of Argentina. The main objective is to evaluate the role of this rodent in the formation of the fossil record. Results indicate that the Plains vizcacha is responsible for the mixing, accumulation, and transport of materials; such as sticks, caliche, dung, feces, and abundant bone remains. Their burrowing activity and the accumulating habits, modifies the landscape, creating environments conducive to the buildup of objects and the reuse by different animals. These characteristics result in very complex associations of materials of different origins; making this rodent an important taphonomic agent with the potential to significantly impact the fossil record.     

Una nueva especie de Neuryurus Ameghino (Mammalia, Glyptodontidae) en el Pleistoceno tardío de la Mesopotamia de Argentina

Among the South American Pleistocene Glyptodontidae (Xenarthra, Cingulata), one of the most scarcely represented genus in the fossil record is Neuryurus Ameghino, in which the only well characterized species, until now, is Neuryurus rudis (Gervais), coming from the Ensenadan (early-middle Pleistocene) of the Pampean region, Argentina. In this contribution, we report and describe a new species of Neuryurus, coming from the Arroyo Feliciano Formation (early Lujanian; ca. 130 ka), Entre Ríos province, Argentina, in a particular palaebiogeographic context, more associated with the western sector of Uruguay and southern Brazil than the Pampean region. From a morphological perspective, this new taxon is characterized by: (a) the remarkable development of the foramina at the exposed surface of the osteoderms of the dorsal carapace, showing un aspect almost spongy; (b) the large diameter of the perforations observed in the ventral surface of the osteoderms, resembling to those present in the dorsal surface of the osteoderms of the Glyptodontidae Doedicurinae; (c) the evident thickness of the osteoderms, as in Glyptodon Owen; (d) area of contact and articulation of adjacent osteoderms very denticulate, with deep osseous interdigitating projections, as in Glyptodon and Glyptotherium Osborn, but here more evident; (e) larger osteoderms of the dorsal carapace showing, in the dorsal surface, many little conical tubercles, having some resemblance to Panochthus tuberculatus Burmeister. The presence of this new species in the early late Pleistocene of the Mesopotamic region is another element that adds to the biogeographical characterization of this particular area, especially evident during the warm and humid pulses of the late Pleistocene. In turn, this species represents the most complete record of the genus outside the Pampean region and partially complete the stratigraphic and geographic distribution of the genus.     

Phylogeny and temporal diversification of darters (Percidae: Etheostomatinae)

Discussions aimed at resolution of the Tree of Life are most often focused on the interrelationships of major organismal lineages. In this study, we focus on the resolution of some of the most apical branches in the Tree of Life through exploration of the phylogenetic relationships of darters, a species-rich clade of North American freshwater fishes. With a near-complete taxon sampling of close to 250 species, we aim to investigate strategies for efficient multilocus data sampling and the estimation of divergence times using relaxed-clock methods when a clade lacks a fossil record. Our phylogenetic data set comprises a single mitochondrial DNA (mtDNA) gene and two nuclear genes sampled from 245 of the 248 darter species. This dense sampling allows us to determine if a modest amount of nuclear DNA sequence data can resolve relationships among closely related animal species. Darters lack a fossil record to provide age calibration priors in relaxed-clock analyses. Therefore, we use a near-complete species-sampled phylogeny of the perciform clade Centrarchidae, which has a rich fossil record, to assess two distinct strategies of external calibration in relaxed-clock divergence time estimates of darters: using ages inferred from the fossil record and molecular evolutionary rate estimates. Comparison of Bayesian phylogenies inferred from mtDNA and nuclear genes reveals that heterospecific mtDNA is present in approximately 12.5% of all darter species. We identify three patterns of mtDNA introgression in darters: proximal mtDNA transfer, which involves the transfer of mtDNA among extant and sympatric darter species, indeterminate introgression, which involves the transfer of mtDNA from a lineage that cannot be confidently identified because the introgressed haplotypes are not clearly referable to mtDNA haplotypes in any recognized species, and deep introgression, which is characterized by species diversification within a recipient clade subsequent to the transfer of heterospecific mtDNA. The results of our analyses indicate that DNA sequences sampled from single-copy nuclear genes can provide appreciable phylogenetic resolution for closely related animal species. A well-resolved near-complete species-sampled phylogeny of darters was estimated with Bayesian methods using a concatenated mtDNA and nuclear gene data set with all identified heterospecific mtDNA haplotypes treated as missing data. The relaxed-clock analyses resulted in very similar posterior age estimates across the three sampled genes and methods of calibration and therefore offer a viable strategy for estimating divergence times for clades that lack a fossil record. In addition, an informative rank-free clade-based classification of darters that preserves the rich history of nomenclature in the group and provides formal taxonomic communication of darter clades was constructed using the mtDNA and nuclear gene phylogeny. On the whole, the appeal of mtDNA for phylogeny inference among closely related animal species is diminished by the observations of extensive mtDNA introgression and by finding appreciable phylogenetic signal in a modest sampling of nuclear genes in our phylogenetic analyses of darters.     

A new calymmate mimosoid polyad from the Miocene of Argentina

A palynomorph with an unequivocal relationship to the eight-grain polyads of the mimosoid genus Calliandra Benth., is described from the Miocene sediments of San Juan Province, Argentina. Comparison of the fossil palynomorph with polyads of the extant Calliandra species shows a resemblance to those which have one, highly specialized, appendiculate monad. The new palynomorph has a rudimentary appendix, apparently transitional in the path leading to the more highly developed appendiculate forms in the extant Calliandra group. This specialized polyad type is considered to be one of the most highly evolved forms in subfamily Mimosoideae. The closest affinity of the new fossil polyad is with the eight-grain calymmate polyads of Calliandra chilensis Benth., a species which has developed in the extra-tropical, xerophilous shrub, habitat of north-central Chile. The disappearance of Calliandra species in San Juan Province is thought to be related to the culmination of the Andean rising, and the consequent interruption to the Pacific Ocean climatic influence. This new discovery is the first fossil record of Calliandra for Argentina, as well as being the most southerly and the oldest. It reinforces the hypothesis of an early origin and diversification for the Leguminosae in Tropical America.     

Revision of the Proteaceae macrofossil record from Patagonia, Argentina

Proteaceae are restricted to the Southern Hemisphere, and of the seven tribes of the subfamily Grevilleoideae, only three (Macadamieae, Oriteae, and Embothrieae) have living members in Argentina. Megafossil genera of Proteaceae recorded from Patagonia includeLomatia, Embothrium, Orites, andRoupala. In this report, we evaluate and revise fossil Argentine Proteaceae on the basis of type material and new specimens. The new collections come from the Tufolitas Laguna del Hunco (early Eocene, Chubut Province), the Ventana (middle Eocene, Río Negro Province), and the Río Ñirihuau (late Oligocene-early Miocene, Río Negro Province) formations, Patagonia, Argentina. We confirm the presence ofLomatia preferruginea Berry,L. occidentalis (Berry) Frenguelli,L. patagonica Frenguelli,Roupala patagonica Durango de Cabrera et Romero, andOrites bivascularis Romero, Dibbern et Gandolfo. Fossils assigned toEmbothrium precoccineum Berry andE. pregrandiflorum Berry are doubtful, and new material is necessary to confirm the presence of this genus in the fossil record of Patagonia. A putative new fossil species of Proteaceae is presented as Proteaceae gen. et sp. indet. Fossil Proteaceae are compared with modern genera, and an identification key for the fossil leaf species is presented. Doubtful historical records of Proteaceae fossils for the Antarctic Peninsula region and Patagonia are also discussed. Based on this revision, the three tribes of Proteaceae found today in Argentina were already present in Patagonia by the early Eocene, where they probably arrived via the Australia-Antarctica-South America connection.     

New host-plant records for the defoliator Ormiscodes amphimone (Fabricius) (Lepidoptera: Saturniidae)

Ormiscodes amphimone (Fabricius) is a phytophagous moth species known to severely defoliate woody species in Chile and Argentina. Here we document new records of O. amphimonehost associations emphasizing the role of Nothofagus pumilio as its primary host in our study area. This new record for Argentina is highly significant given the economic importance of N. pumilio as a timber resource and the potential of O. amphimone to generate extensive outbreaks.